After installing gears on my buddies car we had enough of gears so when another buddy needed gears we took it to this guy that does gears. The crush collar on the gear install was reused when the new gears were installed. The new one was not used by the installer and he claims it doesn't make a difference aslong as its not damaged. My buddies car drives fine with the new 3.73 gears and old crush collar..I remember when we did the gears ourselves, installing the crush collar was the hardest part probably.